Maria Hulens

Predictors of 6-minute walk test results in lean, obese and morbidly obese women.

The aim of this study was first, to assess the presence of medical conditions that might interfere with walking; second, to assess the differences in walking capacity, perceived exertion and physical complaints between lean, obese and morbidly obese women; and third, to identify anthropometric, physical fitness and physical activity variables that contribute to the variability in the distance achieved during a 6‐minute walk test in lean and obese women.

Exercise capacity in lean versus obese women

The aim of this study was to assess the nature and magnitude of the differences in submaximal and maximal exercise capacity parameters between lean and obese women. A total of 225 healthy obese women 18–65 years (BMI> or=30 kg/m2) and 81 non‐athletic lean women (BMI< or=26 kg/m2) were selected. Anthropometric measurements (weight and height), body composition assessment (bioelectrical impedance method) and a maximal exercise capacity test on a bicycle ergometer were performed. Oxygen uptake (VO2), carbon dioxide production (VCO2), expired ventilation (VE), respiratory quotient (RQ), breathing efficiency (VE/VO2), mechanical efficiency (ME) and anaerobic threshold (AT) were calculated. At a submaximal intensity load of 70 W, VO2 (l/min) was larger in the obese women and was already 78% of their peak VO2, whereas in the non‐obese it was only 69% (P=0.0001). VE (l/min) was larger, VE/VO2 did not differ and ME was lower in obese compared to the lean women. AT occurred at the same percentage of peak VO2 in both lean and obese women. At peak effort, achieved load, terminal VO2 (l min−1 kg−1), VE, heart rate, RQ respiratory exchange ratio and perceived exertion were lower in obese subjects compared to the non‐obese. Obese subjects mentioned significantly more musculoskeletal pain as a reason to end the test, whereas in lean subjects it was leg fatigue. Lean women recovered better as after 2 min they were already at 35% of the peak VO2, whereas in the obese women it was 47% (P=0.0001). Our results confirm that exercise capacity is decreased in obesity, both at submaximal and peak intensity, and during recovery. Moreover, at peak effort musculoskeletal pain was an important reason to end the test and not true leg fatigue. These findings are important when designing exercise programs for obese subjects.

Study of differences in peripheral muscle strength of lean versus obese women: an allometric approach

OBJECTIVE: To investigate whether peripheral muscle strength is significantly different between lean and obese women controlled for age and physical activity, using an allometric approach.DESIGN: Cross-sectional study of isometric handgrip and isokinetic leg and trunk muscle strength.SUBJECTS: 173 obese (age 39.9±11.4 y, body mass index (BMI) 37.8±5.3 kg/m2) and 80 lean (age 39.7±12.2 y, BMI 22.0±2.2 kg/m2) women.MEASUREMENTS: Anthropometric measures (weight, height) and body composition (bioelectrical impedance method), isometric handgrip (maximal voluntary contraction on the Jamar dynamometer), isokinetic trunk flexion–extension, trunk rotation, and knee flexion–extension (Cybex dynamometers).RESULTS: Absolute isokinetic strength output (that is, strength uncorrected for fat-free mass) was larger in obese compared to lean women, except for knee flexion and isometric handgrip, which were not significantly different (P>0.05). Pearson correlation coefficients between strength measures and fat-free mass (kg) were low to moderate both in lean (r=0.28–0.53, P<0.05) and in obese (r=0.29–0.49, P<0.001) women. There was no correlation with fat mass (kg) in the lean, whereas in the obese women a weak positive relation could be observed for most isokinetic data (r=0.21–0.39, P<0.01). When correcting for fat-free mass (raised to the optimal exponent determined by allometric scaling), all strength measurements were at least 6% lower in obese when compared to the lean women, except for trunk flexion, which was at least 8% stronger in obese women.DISCUSSION: The higher absolute knee extension strength measures of leg and the similar extension strength of the trunk in the obese sample compared to the lean might be explained by the training effect of weight bearing and support of a larger body mass. However when the independent effect of fat-free mass is removed, these strength measures, as well as oblique abdominal muscle and handgrip strength, turned out to be lower in obese women. These observations could be the reflection of the overall impairment of physical fitness as a consequence of obesity and its metabolic complications.

Trends in BMI among Belgian children, adolescents and adults from 1969 to 1996

OBJECTIVE: To document secular data on changes in the distribution of body mass index (BMI), to determine the probability of overweight at 40 y of age in Belgian males in relation to the presence or absence of overweight at different ages in adolescence, and to estimate tracking of BMI in Belgian males in Belgium aged 12–40 y.DESIGN: Cross-sectional and mixed longitudinal surveys in nationally representative samples of Belgian males and females.SUBJECTS: Cross-sectional—more than 21 000 boys and 9698 girls; to examine secular trends—3164 boys and 5140 girls; to examine tracking—161 males.MEASURES: Body mass and height to determine BMI.RESULTS: In Belgian children the degree of overweight has increased between 1969 and 1993. Tracking of BMI is high in adolescence (r=0.77) and adulthood (r=0.69–0.91) and moderate from adolescence to adulthood (r=0.49). In Belgian males, the probability of overweight at 40 y of age in the presence of overweight at different ages in adolescence is important (odds ratios 5.0–6.9).CONCLUSIONS: Cross-sectional and longitudinal data, trends and tracking of BMI from 1969 until 1996 in Belgium indicate an increase in the degree of childhood overweight and obesity. Moreover, the risk of an overweight male adolescent becoming an overweight adult is substantial. Measures to restrict the Belgian overweight and obesity epidemic should be taken.

Can patients with symptomatic Tarlov cysts be differentiated from patients with specific low back pain based on comprehensive history taking

BackgroundTarlov cysts (TCs) are expanded nerve root sheaths that occur near the dorsal root ganglion and result from increased intraspinal hydrostatic pressure. TCs most frequently affect the lumbosacral plexus and therefore may cause specific symptoms such as perineal pain and neurogenic bladder, bowel, and sphincter problems. It has been estimated that 1% of the population has symptomatic Tarlov cysts (STCs). However, STCs appear to be underdiagnosed, with the pain reported by patients commonly attributed to degenerative alterations seen on MRI. The aim of the present study is to investigate the utility of a comprehensive questionnaire for use by physicians in establishing the diagnosis of STCs.MethodsWe compared questionnaire responses regarding patient history between 33 patients diagnosed with symptomatic TCs and 42 patients with chronic low back pain and sciatica due to disc problems or degenerative or inflammatory disorders. The diagnosis of STCs was confirmed using nerve conduction studies (NCS) and electromyography (EMG) of the sacral myotomes by an expert neurophysiologist.ResultsThe questionnaire responses revealed specific differences in perineal symptoms (perineal pain, dyspareunia, coccygodynia), bowel symptoms (constipation, diarrhea), bladder symptoms (hesitation, retention, frequency), and anal sphincter problems (anal pain, mild fecal incontinence). Additionally, sitting, walking, and straining aggravated pain more frequently in STC patients, and STC patients were more often forced to stop working and/or reduce their social activities.ConclusionsIncluding the above-listed items in the patient history might facilitate differentiation of low back pain and sciatica due to STCs from that due to disc problems or degenerative or inflammatory disorders.